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  <section id="type-objects">
<span id="typeobjects"></span><h1>Type Objects<a class="headerlink" href="#type-objects" title="Permalink to this headline">¶</a></h1>
<span class="target" id="index-0"></span><dl class="type">
<dt id="c.PyTypeObject">
<code class="sig-name descname">PyTypeObject</code><a class="headerlink" href="#c.PyTypeObject" title="Permalink to this definition">¶</a></dt>
<dd><p>The C structure of the objects used to describe built-in types.</p>
</dd></dl>

<dl class="var">
<dt id="c.PyType_Type">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="sig-name descname">PyType_Type</code><a class="headerlink" href="#c.PyType_Type" title="Permalink to this definition">¶</a></dt>
<dd><p>This is the type object for type objects; it is the same object as
<a class="reference internal" href="../library/functions.html#type" title="type"><code class="xref py py-class docutils literal notranslate"><span class="pre">type</span></code></a> in the Python layer.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyType_Check">
int <code class="sig-name descname">PyType_Check</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *o</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_Check" title="Permalink to this definition">¶</a></dt>
<dd><p>Return non-zero if the object <em>o</em> is a type object, including instances of
types derived from the standard type object.  Return 0 in all other cases.
This function always succeeds.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyType_CheckExact">
int <code class="sig-name descname">PyType_CheckExact</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *o</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_CheckExact" title="Permalink to this definition">¶</a></dt>
<dd><p>Return non-zero if the object <em>o</em> is a type object, but not a subtype of
the standard type object.  Return 0 in all other cases.  This function
always succeeds.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyType_ClearCache">
unsigned int <code class="sig-name descname">PyType_ClearCache</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_ClearCache" title="Permalink to this definition">¶</a></dt>
<dd><p>Clear the internal lookup cache. Return the current version tag.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyType_GetFlags">
unsigned long <code class="sig-name descname">PyType_GetFlags</code><span class="sig-paren">(</span><a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a>*<em> type</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_GetFlags" title="Permalink to this definition">¶</a></dt>
<dd><p>Return the <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_flags" title="PyTypeObject.tp_flags"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_flags</span></code></a> member of <em>type</em>. This function is primarily
meant for use with <cite>Py_LIMITED_API</cite>; the individual flag bits are
guaranteed to be stable across Python releases, but access to
<a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_flags" title="PyTypeObject.tp_flags"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_flags</span></code></a> itself is not part of the limited API.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.2.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>The return type is now <code class="docutils literal notranslate"><span class="pre">unsigned</span> <span class="pre">long</span></code> rather than <code class="docutils literal notranslate"><span class="pre">long</span></code>.</p>
</div>
</dd></dl>

<dl class="function">
<dt id="c.PyType_Modified">
void <code class="sig-name descname">PyType_Modified</code><span class="sig-paren">(</span><a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *type</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_Modified" title="Permalink to this definition">¶</a></dt>
<dd><p>Invalidate the internal lookup cache for the type and all of its
subtypes.  This function must be called after any manual
modification of the attributes or base classes of the type.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyType_HasFeature">
int <code class="sig-name descname">PyType_HasFeature</code><span class="sig-paren">(</span><a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *o</em>, int<em> feature</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_HasFeature" title="Permalink to this definition">¶</a></dt>
<dd><p>Return non-zero if the type object <em>o</em> sets the feature <em>feature</em>.
Type features are denoted by single bit flags.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyType_IS_GC">
int <code class="sig-name descname">PyType_IS_GC</code><span class="sig-paren">(</span><a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *o</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_IS_GC" title="Permalink to this definition">¶</a></dt>
<dd><p>Return true if the type object includes support for the cycle detector; this
tests the type flag <a class="reference internal" href="typeobj.html#Py_TPFLAGS_HAVE_GC" title="Py_TPFLAGS_HAVE_GC"><code class="xref py py-const docutils literal notranslate"><span class="pre">Py_TPFLAGS_HAVE_GC</span></code></a>.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyType_IsSubtype">
int <code class="sig-name descname">PyType_IsSubtype</code><span class="sig-paren">(</span><a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *a</em>, <a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *b</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_IsSubtype" title="Permalink to this definition">¶</a></dt>
<dd><p>Return true if <em>a</em> is a subtype of <em>b</em>.</p>
<p>This function only checks for actual subtypes, which means that
<a class="reference internal" href="../reference/datamodel.html#class.__subclasscheck__" title="class.__subclasscheck__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__subclasscheck__()</span></code></a> is not called on <em>b</em>.  Call
<a class="reference internal" href="object.html#c.PyObject_IsSubclass" title="PyObject_IsSubclass"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_IsSubclass()</span></code></a> to do the same check that <a class="reference internal" href="../library/functions.html#issubclass" title="issubclass"><code class="xref py py-func docutils literal notranslate"><span class="pre">issubclass()</span></code></a>
would do.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyType_GenericAlloc">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="sig-name descname">PyType_GenericAlloc</code><span class="sig-paren">(</span><a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *type</em>, Py_ssize_t<em> nitems</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_GenericAlloc" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: New reference.</em><p>Generic handler for the <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_alloc" title="PyTypeObject.tp_alloc"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_alloc</span></code></a> slot of a type object.  Use
Python’s default memory allocation mechanism to allocate a new instance and
initialize all its contents to <code class="docutils literal notranslate"><span class="pre">NULL</span></code>.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyType_GenericNew">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="sig-name descname">PyType_GenericNew</code><span class="sig-paren">(</span><a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *type</em>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *args</em>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *kwds</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_GenericNew" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: New reference.</em><p>Generic handler for the <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_new" title="PyTypeObject.tp_new"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_new</span></code></a> slot of a type object.  Create a
new instance using the type’s <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_alloc" title="PyTypeObject.tp_alloc"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_alloc</span></code></a> slot.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyType_Ready">
int <code class="sig-name descname">PyType_Ready</code><span class="sig-paren">(</span><a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *type</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_Ready" title="Permalink to this definition">¶</a></dt>
<dd><p>Finalize a type object.  This should be called on all type objects to finish
their initialization.  This function is responsible for adding inherited slots
from a type’s base class.  Return <code class="docutils literal notranslate"><span class="pre">0</span></code> on success, or return <code class="docutils literal notranslate"><span class="pre">-1</span></code> and sets an
exception on error.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>If some of the base classes implements the GC protocol and the provided
type does not include the <a class="reference internal" href="typeobj.html#Py_TPFLAGS_HAVE_GC" title="Py_TPFLAGS_HAVE_GC"><code class="xref py py-const docutils literal notranslate"><span class="pre">Py_TPFLAGS_HAVE_GC</span></code></a> in its flags, then
the GC protocol will be automatically implemented from its parents. On
the contrary, if the type being created does include
<a class="reference internal" href="typeobj.html#Py_TPFLAGS_HAVE_GC" title="Py_TPFLAGS_HAVE_GC"><code class="xref py py-const docutils literal notranslate"><span class="pre">Py_TPFLAGS_HAVE_GC</span></code></a> in its flags then it <strong>must</strong> implement the
GC protocol itself by at least implementing the
<a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_traverse" title="PyTypeObject.tp_traverse"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_traverse</span></code></a> handle.</p>
</div>
</dd></dl>

<dl class="function">
<dt id="c.PyType_GetSlot">
void* <code class="sig-name descname">PyType_GetSlot</code><span class="sig-paren">(</span><a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *type</em>, int<em> slot</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_GetSlot" title="Permalink to this definition">¶</a></dt>
<dd><p>Return the function pointer stored in the given slot. If the
result is <code class="docutils literal notranslate"><span class="pre">NULL</span></code>, this indicates that either the slot is <code class="docutils literal notranslate"><span class="pre">NULL</span></code>,
or that the function was called with invalid parameters.
Callers will typically cast the result pointer into the appropriate
function type.</p>
<p>See <code class="xref c c-member docutils literal notranslate"><span class="pre">PyType_Slot.slot</span></code> for possible values of the <em>slot</em> argument.</p>
<p>An exception is raised if <em>type</em> is not a heap type.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
</dd></dl>

<dl class="function">
<dt id="c.PyType_GetModule">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="sig-name descname">PyType_GetModule</code><span class="sig-paren">(</span><a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *type</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_GetModule" title="Permalink to this definition">¶</a></dt>
<dd><p>Return the module object associated with the given type when the type was
created using <a class="reference internal" href="#c.PyType_FromModuleAndSpec" title="PyType_FromModuleAndSpec"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyType_FromModuleAndSpec()</span></code></a>.</p>
<p>If no module is associated with the given type, sets <a class="reference internal" href="../library/exceptions.html#TypeError" title="TypeError"><code class="xref py py-class docutils literal notranslate"><span class="pre">TypeError</span></code></a>
and returns <code class="docutils literal notranslate"><span class="pre">NULL</span></code>.</p>
<p>This function is usually used to get the module in which a method is defined.
Note that in such a method, <code class="docutils literal notranslate"><span class="pre">PyType_GetModule(Py_TYPE(self))</span></code>
may not return the intended result.
<code class="docutils literal notranslate"><span class="pre">Py_TYPE(self)</span></code> may be a <em>subclass</em> of the intended class, and subclasses
are not necessarily defined in the same module as their superclass.
See <a class="reference internal" href="structures.html#c.PyCMethod" title="PyCMethod"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyCMethod</span></code></a> to get the class that defines the method.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.9.</span></p>
</div>
</dd></dl>

<dl class="function">
<dt id="c.PyType_GetModuleState">
void* <code class="sig-name descname">PyType_GetModuleState</code><span class="sig-paren">(</span><a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *type</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_GetModuleState" title="Permalink to this definition">¶</a></dt>
<dd><p>Return the state of the module object associated with the given type.
This is a shortcut for calling <a class="reference internal" href="module.html#c.PyModule_GetState" title="PyModule_GetState"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyModule_GetState()</span></code></a> on the result
of <a class="reference internal" href="#c.PyType_GetModule" title="PyType_GetModule"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyType_GetModule()</span></code></a>.</p>
<p>If no module is associated with the given type, sets <a class="reference internal" href="../library/exceptions.html#TypeError" title="TypeError"><code class="xref py py-class docutils literal notranslate"><span class="pre">TypeError</span></code></a>
and returns <code class="docutils literal notranslate"><span class="pre">NULL</span></code>.</p>
<p>If the <em>type</em> has an associated module but its state is <code class="docutils literal notranslate"><span class="pre">NULL</span></code>,
returns <code class="docutils literal notranslate"><span class="pre">NULL</span></code> without setting an exception.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.9.</span></p>
</div>
</dd></dl>

<section id="creating-heap-allocated-types">
<h2>Creating Heap-Allocated Types<a class="headerlink" href="#creating-heap-allocated-types" title="Permalink to this headline">¶</a></h2>
<p>The following functions and structs are used to create
<a class="reference internal" href="typeobj.html#heap-types"><span class="std std-ref">heap types</span></a>.</p>
<dl class="function">
<dt id="c.PyType_FromModuleAndSpec">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="sig-name descname">PyType_FromModuleAndSpec</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *module</em>, <a class="reference internal" href="#c.PyType_Spec" title="PyType_Spec">PyType_Spec</a><em> *spec</em>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *bases</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_FromModuleAndSpec" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: New reference.</em><p>Creates and returns a heap type object from the <em>spec</em>
(<a class="reference internal" href="typeobj.html#Py_TPFLAGS_HEAPTYPE" title="Py_TPFLAGS_HEAPTYPE"><code class="xref py py-const docutils literal notranslate"><span class="pre">Py_TPFLAGS_HEAPTYPE</span></code></a>).</p>
<p>If <em>bases</em> is a tuple, the created heap type contains all types contained
in it as base types.</p>
<p>If <em>bases</em> is <code class="docutils literal notranslate"><span class="pre">NULL</span></code>, the <em>Py_tp_bases</em> slot is used instead.
If that also is <code class="docutils literal notranslate"><span class="pre">NULL</span></code>, the <em>Py_tp_base</em> slot is used instead.
If that also is <code class="docutils literal notranslate"><span class="pre">NULL</span></code>, the new type derives from <a class="reference internal" href="../library/functions.html#object" title="object"><code class="xref py py-class docutils literal notranslate"><span class="pre">object</span></code></a>.</p>
<p>The <em>module</em> argument can be used to record the module in which the new
class is defined. It must be a module object or <code class="docutils literal notranslate"><span class="pre">NULL</span></code>.
If not <code class="docutils literal notranslate"><span class="pre">NULL</span></code>, the module is associated with the new type and can later be
retreived with <a class="reference internal" href="#c.PyType_GetModule" title="PyType_GetModule"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyType_GetModule()</span></code></a>.
The associated module is not inherited by subclasses; it must be specified
for each class individually.</p>
<p>This function calls <a class="reference internal" href="#c.PyType_Ready" title="PyType_Ready"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyType_Ready()</span></code></a> on the new type.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.9.</span></p>
</div>
</dd></dl>

<dl class="function">
<dt id="c.PyType_FromSpecWithBases">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="sig-name descname">PyType_FromSpecWithBases</code><span class="sig-paren">(</span><a class="reference internal" href="#c.PyType_Spec" title="PyType_Spec">PyType_Spec</a><em> *spec</em>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *bases</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_FromSpecWithBases" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: New reference.</em><p>Equivalent to <code class="docutils literal notranslate"><span class="pre">PyType_FromModuleAndSpec(NULL,</span> <span class="pre">spec,</span> <span class="pre">bases)</span></code>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
</dd></dl>

<dl class="function">
<dt id="c.PyType_FromSpec">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="sig-name descname">PyType_FromSpec</code><span class="sig-paren">(</span><a class="reference internal" href="#c.PyType_Spec" title="PyType_Spec">PyType_Spec</a><em> *spec</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_FromSpec" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: New reference.</em><p>Equivalent to <code class="docutils literal notranslate"><span class="pre">PyType_FromSpecWithBases(spec,</span> <span class="pre">NULL)</span></code>.</p>
</dd></dl>

<dl class="type">
<dt id="c.PyType_Spec">
<code class="sig-name descname">PyType_Spec</code><a class="headerlink" href="#c.PyType_Spec" title="Permalink to this definition">¶</a></dt>
<dd><p>Structure defining a type’s behavior.</p>
<dl class="member">
<dt id="c.PyType_Spec.PyType_Spec.name">
const char* <code class="sig-name descname">PyType_Spec.name</code><a class="headerlink" href="#c.PyType_Spec.PyType_Spec.name" title="Permalink to this definition">¶</a></dt>
<dd><p>Name of the type, used to set <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_name" title="PyTypeObject.tp_name"><code class="xref c c-member docutils literal notranslate"><span class="pre">PyTypeObject.tp_name</span></code></a>.</p>
</dd></dl>

<dl class="member">
<dt id="c.PyType_Spec.PyType_Spec.basicsize">
int <code class="sig-name descname">PyType_Spec.basicsize</code><a class="headerlink" href="#c.PyType_Spec.PyType_Spec.basicsize" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>

<dl class="member">
<dt id="c.PyType_Spec.PyType_Spec.itemsize">
int <code class="sig-name descname">PyType_Spec.itemsize</code><a class="headerlink" href="#c.PyType_Spec.PyType_Spec.itemsize" title="Permalink to this definition">¶</a></dt>
<dd><p>Size of the instance in bytes, used to set
<a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_basicsize" title="PyTypeObject.tp_basicsize"><code class="xref c c-member docutils literal notranslate"><span class="pre">PyTypeObject.tp_basicsize</span></code></a> and
<a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_itemsize" title="PyTypeObject.tp_itemsize"><code class="xref c c-member docutils literal notranslate"><span class="pre">PyTypeObject.tp_itemsize</span></code></a>.</p>
</dd></dl>

<dl class="member">
<dt id="c.PyType_Spec.PyType_Spec.flags">
int <code class="sig-name descname">PyType_Spec.flags</code><a class="headerlink" href="#c.PyType_Spec.PyType_Spec.flags" title="Permalink to this definition">¶</a></dt>
<dd><p>Type flags, used to set <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_flags" title="PyTypeObject.tp_flags"><code class="xref c c-member docutils literal notranslate"><span class="pre">PyTypeObject.tp_flags</span></code></a>.</p>
<p>If the <code class="docutils literal notranslate"><span class="pre">Py_TPFLAGS_HEAPTYPE</span></code> flag is not set,
<a class="reference internal" href="#c.PyType_FromSpecWithBases" title="PyType_FromSpecWithBases"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyType_FromSpecWithBases()</span></code></a> sets it automatically.</p>
</dd></dl>

<dl class="member">
<dt id="c.PyType_Spec.PyType_Spec.slots">
<a class="reference internal" href="#c.PyType_Slot" title="PyType_Slot">PyType_Slot</a> *<code class="sig-name descname">PyType_Spec.slots</code><a class="headerlink" href="#c.PyType_Spec.PyType_Spec.slots" title="Permalink to this definition">¶</a></dt>
<dd><p>Array of <a class="reference internal" href="#c.PyType_Slot" title="PyType_Slot"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyType_Slot</span></code></a> structures.
Terminated by the special slot value <code class="docutils literal notranslate"><span class="pre">{0,</span> <span class="pre">NULL}</span></code>.</p>
</dd></dl>

</dd></dl>

<dl class="type">
<dt id="c.PyType_Slot">
<code class="sig-name descname">PyType_Slot</code><a class="headerlink" href="#c.PyType_Slot" title="Permalink to this definition">¶</a></dt>
<dd><p>Structure defining optional functionality of a type, containing a slot ID
and a value pointer.</p>
<dl class="member">
<dt id="c.PyType_Slot.PyType_Slot.slot">
int <code class="sig-name descname">PyType_Slot.slot</code><a class="headerlink" href="#c.PyType_Slot.PyType_Slot.slot" title="Permalink to this definition">¶</a></dt>
<dd><blockquote>
<div><p>A slot ID.</p>
<p>Slot IDs are named like the field names of the structures
<a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyTypeObject</span></code></a>, <a class="reference internal" href="typeobj.html#c.PyNumberMethods" title="PyNumberMethods"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyNumberMethods</span></code></a>,
<a class="reference internal" href="typeobj.html#c.PySequenceMethods" title="PySequenceMethods"><code class="xref c c-type docutils literal notranslate"><span class="pre">PySequenceMethods</span></code></a>, <a class="reference internal" href="typeobj.html#c.PyMappingMethods" title="PyMappingMethods"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyMappingMethods</span></code></a> and
<a class="reference internal" href="typeobj.html#c.PyAsyncMethods" title="PyAsyncMethods"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyAsyncMethods</span></code></a> with an added <code class="docutils literal notranslate"><span class="pre">Py_</span></code> prefix.
For example, use:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">Py_tp_dealloc</span></code> to set <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_dealloc" title="PyTypeObject.tp_dealloc"><code class="xref c c-member docutils literal notranslate"><span class="pre">PyTypeObject.tp_dealloc</span></code></a></p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">Py_nb_add</span></code> to set <a class="reference internal" href="typeobj.html#c.PyNumberMethods.nb_add" title="PyNumberMethods.nb_add"><code class="xref c c-member docutils literal notranslate"><span class="pre">PyNumberMethods.nb_add</span></code></a></p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">Py_sq_length</span></code> to set <a class="reference internal" href="typeobj.html#c.PySequenceMethods.sq_length" title="PySequenceMethods.sq_length"><code class="xref c c-member docutils literal notranslate"><span class="pre">PySequenceMethods.sq_length</span></code></a></p></li>
</ul>
<p>The following fields cannot be set at all using <a class="reference internal" href="#c.PyType_Spec" title="PyType_Spec"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyType_Spec</span></code></a> and
<a class="reference internal" href="#c.PyType_Slot" title="PyType_Slot"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyType_Slot</span></code></a>:</p>
<ul class="simple">
<li><p><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_dict" title="PyTypeObject.tp_dict"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_dict</span></code></a></p></li>
<li><p><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_mro" title="PyTypeObject.tp_mro"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_mro</span></code></a></p></li>
<li><p><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_cache" title="PyTypeObject.tp_cache"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_cache</span></code></a></p></li>
<li><p><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_subclasses" title="PyTypeObject.tp_subclasses"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_subclasses</span></code></a></p></li>
<li><p><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_weaklist" title="PyTypeObject.tp_weaklist"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_weaklist</span></code></a></p></li>
<li><p><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_vectorcall" title="PyTypeObject.tp_vectorcall"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_vectorcall</span></code></a></p></li>
<li><p><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_weaklistoffset" title="PyTypeObject.tp_weaklistoffset"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_weaklistoffset</span></code></a>
(see <a class="reference internal" href="structures.html#pymemberdef-offsets"><span class="std std-ref">PyMemberDef</span></a>)</p></li>
<li><p><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_dictoffset" title="PyTypeObject.tp_dictoffset"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_dictoffset</span></code></a>
(see <a class="reference internal" href="structures.html#pymemberdef-offsets"><span class="std std-ref">PyMemberDef</span></a>)</p></li>
<li><p><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_vectorcall_offset" title="PyTypeObject.tp_vectorcall_offset"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_vectorcall_offset</span></code></a>
(see <a class="reference internal" href="structures.html#pymemberdef-offsets"><span class="std std-ref">PyMemberDef</span></a>)</p></li>
</ul>
<p>The following fields cannot be set using <a class="reference internal" href="#c.PyType_Spec" title="PyType_Spec"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyType_Spec</span></code></a> and
<a class="reference internal" href="#c.PyType_Slot" title="PyType_Slot"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyType_Slot</span></code></a> under the limited API:</p>
<ul class="simple">
<li><p><a class="reference internal" href="typeobj.html#c.PyBufferProcs.bf_getbuffer" title="PyBufferProcs.bf_getbuffer"><code class="xref c c-member docutils literal notranslate"><span class="pre">bf_getbuffer</span></code></a></p></li>
<li><p><a class="reference internal" href="typeobj.html#c.PyBufferProcs.bf_releasebuffer" title="PyBufferProcs.bf_releasebuffer"><code class="xref c c-member docutils literal notranslate"><span class="pre">bf_releasebuffer</span></code></a></p></li>
</ul>
<p>Setting <code class="xref c c-data docutils literal notranslate"><span class="pre">Py_tp_bases</span></code> or <code class="xref c c-data docutils literal notranslate"><span class="pre">Py_tp_base</span></code> may be
problematic on some platforms.
To avoid issues, use the <em>bases</em> argument of
<code class="xref py py-func docutils literal notranslate"><span class="pre">PyType_FromSpecWithBases()</span></code> instead.</p>
</div></blockquote>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.9: </span>Slots in <a class="reference internal" href="typeobj.html#c.PyBufferProcs" title="PyBufferProcs"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyBufferProcs</span></code></a> in may be set in the unlimited API.</p>
</div>
</dd></dl>

<dl class="member">
<dt id="c.PyType_Slot.PyType_Slot.pfunc">
void *<code class="sig-name descname">PyType_Slot.pfunc</code><a class="headerlink" href="#c.PyType_Slot.PyType_Slot.pfunc" title="Permalink to this definition">¶</a></dt>
<dd><p>The desired value of the slot. In most cases, this is a pointer
to a function.</p>
<p>May not be <code class="docutils literal notranslate"><span class="pre">NULL</span></code>.</p>
</dd></dl>

</dd></dl>

</section>
</section>


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